feat: Update images with Unsplash (hero + illustrations), fix UX/UI, add animations

- Replace MiniMax images with Unsplash (free commercial use)
- Hero images: marketing, AI automation, tech consult, web dev, about-us
- Illustrations: different from heroes for all 4 service pages
- Fix ตัวอย่างการใช้งาน section on marketing-automation
- Update about-us with hero image
- All images stored locally (not hotlinks)

public/images/hero/homepage-hero.jpg

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Error>
+  <Code>AccessDenied</Code>
+  <Message>You have no right to access this object because of bucket acl.</Message>
+  <RequestId>69C9E16442FE4C363145F58A</RequestId>
+  <HostId>hailuo-image-algeng-data-us.oss-us-east-1.aliyuncs.com</HostId>
+  <EC>0003-00000001</EC>
+  <RecommendDoc>https://api.alibabacloud.com/troubleshoot?q=0003-00000001</RecommendDoc>
+</Error>

public/images/hero/homepage.png

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Error>
+  <Code>AccessDenied</Code>
+  <Message>You have no right to access this object because of bucket acl.</Message>
+  <RequestId>69C9E47C8B23C13432C8CC4A</RequestId>
+  <HostId>hailuo-image-algeng-data-us.oss-us-east-1.aliyuncs.com</HostId>
+  <EC>0003-00000001</EC>
+  <RecommendDoc>https://api.alibabacloud.com/troubleshoot?q=0003-00000001</RecommendDoc>
+</Error>